Re: LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July 25 telecon)

From: Jeff Heflin <heflin@cse.lehigh.edu>
Subject: Re: LANG: closing issue 4.6 (was Re: ADMIN: Draf agenda for July  25     telecon)
Date: Wed, 24 Jul 2002 13:57:09 -0400

> Peter,
> 
> Thanks for this message. I think it helps clarify the issue. To further
> elucidate things, could you answer a question I have about option 2?
> 
> It seems to me the option 2 leads to non-monotonicity. Consider the
> following classes with extensions:
> 
> foo type Class.
> bar type Class.
> A type foo.
> B type foo.
> A type bar.
> B type bar.
> 
> Since sameClassAs only means that two classes have the same extension,
> then foo sameClassAs bar is a valid entailment, isn't it? 

No.  There are interpretations of the above KB where foo and bar have
different extensions.  All that is known is that the denotations of both A
and B belong to both foo and bar.

Similarly, 

  John friend Peter .
  
does not entail that John belongs to the class of objects that have at most
one friend.

[...]

> Jeff

Received on Wednesday, 24 July 2002 14:10:48 UTC